From U.S. Pat. No. 4,854,523 it is known to arrange the spinning units in pairs in a yarn spinning machine, e.g. a pair of air jet spinning nozzles, and to jointly wind up the separate yarns being spun onto a joint bobbin. This method is preferable if the two yarns are to be subsequently twisted, because a rewinding can be avoided thereby. False twist yarns produced with air jet spinning nozzles are well suited for subsequent twisting. Twisted false twist yarns are nearly equivalent to twisted ring spinning yarns with respect to quality and can be produced substantially less expensively.
Automatic service robots are known (e.g. EP 417 662) for automatically repairing yarn breakages or otherwise restarting spinning operations in air jet spinning machines. These known automatic operating devices cannot be used in spinning machines according to U.S. Pat. No. 4,854,523 without implementing additional measures.